The desert planet Zolpha-Thura, the 1980s. Giant intelligent megalomaniac cactus Meglos is planning to conquer the galaxy but first it needs the dodecahedron, a powerful energy source currently on the planet Tigella. To get it back Meglos recruits a band of galactic mercenaries and hatches a cunning scheme requiring it to impersonate the Doctor...
| Name | Type | Role | |
|---|---|---|---|
| John Flanagan, Andrew McCulloch | Writer | ||
| Simon Shaw | Guest Star | ||
| Jacqueline Hill | Guest Star | ||
| Edward Underdown | Guest Star | ||
| Christopher Owen | Guest Star | ||
| Frederick Treves | Guest Star | ||
| Crawford Logan | Guest Star | ||
| Bill Fraser | Guest Star | ||
| Colette Gleeson | Guest Star | ||
| Terence Dudley | Director |